Glasgow
low temperature separator



Jan. 5, 1965 c. o. GLASGOW LOW TEMPERATURE SEPARATOR 4 Sheets-Sheet 1Original Filed Dec 24. 1958 GAS OUTLET CLARENCE o. GLASGOW l}i -1. BY :l

ATTORNEY Jan. 5, 1965 c. o. GLASGOW LOW TEMPERATURE SEPARATOR OriginalFiled Dec. 24, 1958 4 Sheets-Sheet 2 INVENTOR. CLARENCE O. GLASGOW BYdd, K

ATTORNEY Jan. 5, 1965 c. o. GLASGOW Re. 25,708

LOW rmnm-rurm summon Original Filed Dec. 24, 1958 4 Sheets-Sheet. 4

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ATTORNEY United States Patent Otifice Re. 25,708 Reissued Jan. 5, 196525,703 LOW TEMPERATURE SEPARATOR Clarence 0. Glasgow, Tulsa, Okla,assignor to National Tank Company, Tulsa, Okla, a corporation of NevadaOriginal No. 2,990,691, dated July 4, 1961, Ser. No.

782,979, Dec. 24, 1958. Application for reissue June 19, 1963, Ser. No.290,279

11 Claims. (Cl. 62--12) Matter enclosed in heavy brackets appears in theoriginal patent but forms no part of this reissue specification; matterprinted in italics indicates the additions made by reissue.

This invention relates to well fluid separators. More specifically, theinvention relates to low temperature separators wherein predominantlygaseous well streams of relatively high pressure are stripped of readilyliquifiable hydrocarbons and water.

The present embodiment of the invention is useful Where a so-called gas,or gas-oil well, is flowing at relatively high pressures and producingconsiderable quantities of gas along with various liquifiablehydrocarbons and Water or Water vapor. Wells vary widely as to theirflowing pressure, temperature and the composition of their flow stream.It may be desirable to remove practically all the water and water vaporfrom the flow stream. It may be desirable to only reduce the dew pointto a moderate figure and strip the flow stream as completely as possibleof readily liquifiable hydrocarbons, or to allow a portion of suchhydrocarbons to remain in the residual gas. Low temperature separationsystems providing these functions generally include a vessel into whichthe well stream is choked to reduce its pressure in order for the Waterand hydrocarbons to liquefy in accordance with the Joules-Thompsoneffect. In general, it is common to maintain a collection of the liquidsin the vessel, heated to a temperature which will melt the ice and/orhydrates formed when the well stream is cooled by pres sure reduction. 7

It has been common to maintain the elevated temperature of the liquidbath of a low temperature separation vessel by heat transfer coilsmounted directly in the liquid bath. These coils can be directly heatedby circulating the well stream therethrough, steam or the products of acombustion process. These sources of heat, outside the vessel, have madethe system physically bulky, expensive to fabricate and difficult totransport. Further, the constant threat of rupture of the heat exchangewalls in the relatively high pressure of the vessel threatens loss oflife and property.

A primary object of the present invention is to mount a source of heatwithin the vessel of a low temperature separation unit in such a waythat the unit will be compact, inexpensively manufactured and safe tooperate.

Another object of the invention is to mount a source of direct heatWithin the vessel of the low temperature separation system so its heatwill be transmitted indirectly to the liquid bath of the vessel.

Another object of the invention is to supply heat for the liquid bath ofa low temperature separator with a separate liquid which is directlyheated within a closed system within the vessel. Another object of theinvention is to provide a closed system for a heated body of liquid inthe bath of the low temperature separation vessel, the body of liquidbeing heated from a source of combustion also mounted within the vessel.

Another object is to provide a body of heating liquid circulating in azone within the liquid bath of a low temperature separator vessel andheat exchanging with the choke for the well stream.

Another object is to dissipate the heat of a heating body of liquid tothe liquid bath of a low temperature separator at multiple points with aconducting structure.

Another object is to divert the choked well stream of a low temperatureseparator vessel downwardly toward its liquid bath while insulating thestream from the radiated heat of a heating source for the bath and thenreversing direction of flow of the cooled gaseous portion of the wellstream upwardly into heat exchange with the heating source, whereby thegaseous portion acquires sufficient heat to eliminate any hydrates inthe path of the gaseous portion to its outlet from the vessel.

The present invention contemplates mounting a completely containedsource of heat within the interior of the vessel of a low temperatureseparation system for predominantly gaseous well streams to provide acompact, inexpensive unit which can be readily transported.

The invention further contemplates the combustion of a fuel within achamber mounted in the vessel of a low temperature separation system.The heat of the combustion chamber is transmitted to the bath through aheat transfer medium for mechanically isolating the walls of the highpressure vessel from the walls of the combustion chamber. The inventionfurther contemplates the heating zone of the combustion chamber and heattransfer medium extending centrally through the vessel of the lowtemperature separation system to make the'unit compact and readilyavailable for service and instrumentation. The invention furthercontemplates a transfer medium of liquid circulating in a chambermounted within the liquid bath of the vessel of the low temperatureseparation system. A fuel-fired combustion chamber is mounted within theheating liquid chamber. A heating liquid is selected which will notfreeze at expected ambient temperatures during intermittent operation ofthe system.

The invention further contemplates that the heating liquid circulatingthrough the bath of the vessel be passed through a conduit external ofthe vessel and into heat exchange with the choke across which thepressure of the well stream is reduced into the vessel.

The invention further contemplates the chamber for the heating liquidmounted in the bath of the vessel of the low temperature separationsystem having fins mounted thereon and extending into the liquid bath inorder to dissipate the heat of the liquid into the liquid bath atmultiple points.

The invention further contemplates a baflie structure between the chokeinlet to the vessel and the chamber for the heating liquid which willdivert the well stream downwardly toward the bath and insulate thedownwardlydiverted stream from heat radiating from the heating liquidchamber. The baffle then directs reversal of the cooled gaseous portionof the well stream in order to discharge ice and hydrates into theliquid bath from the gaseous portion and to pass the remaining gaseousportion of the well stream into heat exchange relation with the heatingliquid chamber prior to the gaseous portion of the well stream passingfrom the vessel, whereby the gaseous portion acquires sufficient heat toeliminate any hydrates in the path of the gaseous portion of the wellstream to its outlet from the vessel.

Other objects, advantages and features of this invention will becomeapparent to one skilled in the art upon consideration of the writtenspecification, appended claims and attached drawing wherein:

FIG. 1 is a sectioned elevation of the preferred embodiment of theinvention in a vertical low temperature separation vessel;

FIG. 2 is a plan view of a cross-section taken along lines 2-2 of FIG.1',

FIG. 3 is a plan view of a cross section taken along lines 3-3 of FIG.1;

FIG. 4 is a sectioned elevation of a low temperature separation vesselsimilar to FIG. 1 with a different type of heat source and control ofthe liquid phases of the well stream;

FIG. 5 is a sectioned elevation of a horizontal low temperatureseparation vessel embodying certain features of the invention; and

FIG. 6 is a sectioned elevation of a horizontal low temperatureseparation vessel similar to that of FIG. 5 and having a diiferentarrangement of the heat source.

FIG. 1 illustrates the essential structure associated with the vessel ofa low temperature separation system, the combination embodying thepresent invention. The vessel shell 1 is cylindrical and is mounted withits longitudinal axis vertical. The well stream is brought to vessel 1by conduit 2. The high pressure of the well stream, generally rangingfrom 1500 lbs. per sq. inch upward, is reduced through a conventionalchoke 3.

The reduction in pressure of the well stream, through choke 3, lowersthe temperature in accordance with the Joules-Thompson effect. Thecooling condenses, or liquifies, both hydrocarbons and Water of the wellstream. These liquids collect in a bath 4. The remaining gaseous phaseof the well stream is drawn off the vessel 1 through conduit 5. The gasof conduit 5 is the primary product of the system, being dehydrated inthis manner and at a pressure which will be accepted into a pipe line.

Hydrates that form when the well stream has its pressure reduced are acommon hazard. These products will physically block, or clog, the gasspace within vessel 1. A common practice is to heat bath 4 to atemperature which will melt hydrates as these hydrates precipitate intothe bath as they form.

Bath 4 can be separated into its water and hydrocarbon components andthe components separately withdrawn. In FIG. 1 all liquids of bath 4 arewithdrawn through conduit 6. Valve 7 in conduit 6 regulates the liquidwithdrawal from bath 4. Valve 7 is controlled by float 8 which developsa fluid pressure in pipe 9. Pipe 9 is now shown connected to thediaphragm of valve 7 to avoid drawing complications.

The temperature of bath 4 is controlled by a temperature sensing elementwhich regulates heat input to the bath. The arrangement of the heatsource Within the vessel, under the concepts of the invention, gives aphysically compact system, yet one that can be inexpensivelymanufactured and is safe to operate.

FIG. 1 illustrates the source of heat as a firetube exposed directly tothe combustion of fuel gas. Details of the flame arrestor, fuel-airmixer and burner are not illustrated. These elements are containedWithin housing 10. Fuel gas is brought to housing 10 by conduit 11.Valve 12 regulates the flow of fuel gas through conduit 11. Valve 12 iscontrolled by a temperature sensing system which will be describedsubsequently.

The products of combustion of fuel gas from conduit 11 are passedthrough firetube 13. Tube 13, fired from housing 10, is arrangedsubstantially completely within vessel 1. The combination of lowtemperature separation vessel and heat source is very compact whencompared with externally placed heat sources. Further the mounting ofthis direct source of heat, so its heat will be transmitted to bath 4indirectly, offers further advantages under concepts of the invention.

A closed system of liquid heat transfer medium is combined with vessel 1and firetube 3. A conduit 14 is mounted in the vessel 1 about itsvertically extended longitudinal axis. Conduit 14 opens into reservoircompartments at the top and bottom of the vessel 1. Conduits 17 and 18extend from these reservoir compartments to a' acket 19, about choke 3,to complete the closed system. This closed system may be filled with anymaterial 20 vhich will not freeze in cold weather and yet will funcionto transfer the heat of tube 13 to the liquid bath 4 1nd parts of vessel1 on which hydrates might stick and collect. Glycol is one satisfactorymedium for this purpose.

As the heat of tube 13 is transmitted to glycol 20, the glycol willcirculate under the force of thermosyphon action. Arrows are used toindicate the direction of glycol movement. In this path the glycol body20 becomes a heat source for bath 4, gas in the upper part of vessel 1and the choke 3. Thus hydrate formation is eliminated, and prevented, atmultiple locations throughout the system.

The combination of direct heat source tube 13 and heated body of liquidbetween the tube and interior of vessel 1, but both within the vessel 1,has several advantages. The compactness of the arrangement has beendiscussed. Further, the danger of vessel 1 being ruptured, andthe-relatively high pressure within vessel 1 escaping, is reduced. Tube13 may fail from direct exposure to the fuel gas flame, but rupture ofthese walls in this combination would only release the liquid body 20,leaving the Vessel 1 intact. Obviously the danger to operating personneland equipment is less than in arrangements where there is directexposure of the vessel 1 interior to the combustion.

It can now be seen that an objective of the combination is to maintain atemperature differential between bath 4 and glycol 20. To maintain thisdifferential, temperature response element 21 is placed in bath 4 andelement 22 is placed in glycol 20. The fluid pressure control signalsdeveloped by these elements are compared and their difference applied tothe control of valve 12. It is not seen as necessary to disclose thissystem in greater detail. By this system the heat input tothe vessel 1is regulated to effectively eliminate and prevent hydrate formation inthe vessel 1 or choke 3.

The heat of glycol body 20, transmitted through the walls of conduit 14,is dissipated in bath 4 by a fin structure. A series of metallic plates,as fins, are spaced about conduit 14. These fins 23 are attacheddirectly to the walls of conduit 14 and dissipate, by conduction, theheat of liquid 20 into the liquid bath 4 at multiple locations.- Theefliciency gained by this dissipating means is a new result in thesecombinations of low temperature separator vessels and heat sources fortheir baths.

FIG. 2 shows the fins 23, conduit 14, tube 13 combination within vessel1 to further advantage. The compactness and simplicity of thearrangement is obvious from FIG. 2 and the result is a distinct advancein the art of low temperature separation.

FIG. 3 is to be taken in connection with FIG. 1 to show the flow path ofthe well stream from conduit 2 to further advantage. The well stream ofconduit 2, out of choke 3 strikes diverter plate 24 and is whirled in acircular path about the interior of vessel 1. FIG. 3 shows the circularpath and FIG. 1 indicates the downward course, followed by a sharpreversal upward, of the path, toward outlet conduit 5.

Bafile structure 25 performs several functions. First, the baffle 25enters into the definition of the circular flow path of the well streamaround the interior wall of vessel 1. Second, the bafiie insulates thedownwardly directed well stream from the heat of conduit 14 so the fulleffect of the pressure-reduction cooling is more eflicient indehydrating the well stream. Third, the baflie defines a flow path forthe well stream as it is sharply diverted upward from the surface ofbath 4. The sharp change in direction throws the liquefied components,and hydrates, into bath 4. The remaining gas is then flowed over the external surface of conduit 14 to be warmed so hydrates will not form, andthose already entrained in the gas will be melted.

FIG. 4 has been established to elaborate on the concepts bf theinvention illustrated in FIG. 1. A low temperature separation vessel 30is shown, generally similar to vessel 1 of FIG. 1. A well stream isbrought to. the:

.5 vessel by conduit 31 and dehydrated gas is removed through conduit32.

In FIG. 1 it was illustrated that all liquids could be removed through asingle conduit. FIG. 4 now illustrates how the liquid may be permittedto separate into its oil and water contents and these separatelyremoved. The liquid bath is shown as comprised of oil strata 33 on topof a water strata 34. The interface between these two liquids is shownas maintained at 35. One means of detecting this interface 35 isindicated as embodied in a probe 36 with which a fluid pressure controlsignal is developed through a system in an instrument at 37.

The probe 36 may be a capacitance type incorporated in a circuit, asshown in Gunst et al. 2,720,624, within instrument 37. The transductionof the probe signal into a control fluid pressure in pipe 38 is wellwithin the skill of those practicing the control art. The water drawnfrom body 34, through conduit 39 is controlled by valve 40. Valve 40 isregulated by the signal in pipe 38 to maintain interface 35 at a fixedspatial relationship with probe 36.

Oil from body 33 is drawn from vessel 1 through conduit 41. Valve 42controls the withdrawal of oil and is regulated by float 43 asillustrated in FIG. 1.

FIG. 4 illustrates a closed system of circulating heat exchange liquidvery similar to that illustrated in FIG. 1. Additionally, this circuitis illustrated as incorporating a heat exchanger 44 with which the wellstream through conduit 31 is warmed a desirable amount prior to passingthrough choke 45. Thus, is illustrated the further flexibility of thisclosed system of heat exchange medium for applying heat to multiplelocations throughout a low tem perature separation system.

Another feature illustrated by FIG. 4 is that of direct heating of theheat exchange medium with other heat sources than the gas fired tubeillustrated in FIG. 1. If available, it is well within the scope of theinvention to include a conduit 46 within tube 47 to introduce heat intothe heat exchange medium.

Conduit 46 may be coils circulating steam from a source not illustrated.Other forms of such heat exchangers are conceivable, and theircombination with a body of heat exchange-medium for indirectlytransmitting heat to a low temperature separation system falls withinthe scope of the present invention.

FIGS. and 6 should be taken together in disclosing the furtherflexibility of the invention. These figures illustrate low temperatureseparation vessels with their longitudinal axes horizontally extended.Low temperature systems including similar vessels are illustrated inWalker et al. 2,747,002. The structure embodying the concepts of theinvention is readily combined with these horizontal vessels.

The sole difference between the vessels of FIGS. 5 and 6 are theirlengths. The form of the novel structure combined with the FIG. 5 vesseloperates with somewhat greater efficiency with a bath of shorterlongitudinal dimension than the bath of FIG. 6.

FIG. 5 illustrates a low temperature separator vessel 50 with a liquidbath 51 maintained therein. Firetube 52 is illustrated extendingvertically up through vessel 5%] and its bath 51. Jacket shell 53 isarranged about firetube 52 and contains the liquid heat exchange mediumwhich transmits heat of the products of combustion of tube 52 to bath51, and other locations in the low temperature separator system.

The liquid heat exchange medium is thermosyphonically circulated fromthe top of jacket-shell 53 through a system of conduits heat exchangingwith choke jacket 54 and spinner-baflie 55. Additionally, fins 56dissipate the heat of the heat exchange medium through multiplelocations in the bath 51.

FIG. 6 shows an elongated low temperature separation vessel 60,horizontally extended with a liquid-bath 61 maintained therein. Firetube62, in contrast to the arrangement of FIG. 5, is shown horizontallyextended in 6 bath 51 for a substantial portion of its length and thentaken from the top of vessel 60. Jacket shell 63 is arranged aboutfiretube 62 to contain the liquid heat exchange medium. Thelongitudinally extended arrangement of jacket shell 63, withheat-dissipating fins 64, will more efficiently distribute heat to bath61 than the FIG. 5 arrangement.

From the foregoing it will be seen that this invention is one welladapted to attain all of the ends and objects hereinabove set forth,together with other advantages which are obvious and which are inherentto the apparatus.

It will be understood that certain features and subcombinations are ofutility and may be employed without reference to other features andsubcombinations. This is contemplated by and is within the scope of theclaims.

As many possible embodiments may be made of the invention withoutdeparting from the scope thereof, it is to be understood that all matterherein set forth or shown in the accompanying drawings is to beinterpreted as illustrative and not in a limiting sense.

The invention having been described, what is claimed [1. A lowtemperature separation system for high pressure hydrocarbon well streamsincluding,

a high pressure vessel receiving the well stream,

a choke through which the well stream is received into the high pressurevessel and reduced in pressure to condense the preponderant part of thehydrocarbons and dehydrate the gaseous portion of the well stream,

a liquid bath in the high pressure vessel arranged to receive hydratesdirectly therein as the hydrates are formed when the pressure of thewell stream is reduced,

an outlet for the dehydrated gas above the level of the liquid bath,

and a source of heat mounted in the vessel and arranged in the liquidbath to maintain the bath at a temperature which will melt the hydratesreceived therein, and the source also extending substantially throughthe length of the gas flow path to the outlet so as to prevent hydratesfrom forming an obstruction to the gas flow a the outlet] 2. A lowtemperature separation system for high pressure hydrocarbon well streamsincluding,

a [high pressure] vessel receiving the well stream,

a choke through which the well stream is received into the [highpressure] vessel and reduced in pressure to condense the preponderantpart of the hydrocarbons and dehydrate the gaseous portion of the wellstream,

a liquid bath in the [high pressure] vessel arranged to receive hydratesdirectly therein as the hydrates are formed when thepressure of the wellstream is reduced,

an outlet for the dehydrated gas above the level of the liquid bath,

and a source of heat mounted in the vessel and arranged in the liquidbath to'maintain the bath at a temperature which will melt the hydratesreceived therein, and the source also extending substantially throughthe length of the gas flow path to the outlet so as to prevent hydratesfrom forming an obstruction to the gas flow at the outlet comprising,

a direct source of heat operated at low pressure,

and a chamber of heat exchange liquid about the low pressure source ofheat and in heat exchange contact with the liquid bath and with the gasflowing to the outlet.

3. A low temperature separation system for high pressure hydrocarbonwell streams including;

a [high pressure] vessel receiving the well stream;

- a choke through which the well stream is received into the [highpressure] vessel and reduced in pressure to condense the preponderantpart of the hydrocarbons and dehydrate the gaseous portion of the wellstream;

a liquid bath in the [high pressure] vessel arranged to receive hydratesdirectly therein as the hydrates are formed when the pressure of thewell stream is re duced;

an outlet for the dehydrated gas above the level of the liquid bath;

and a source of heat mounted in the vessel and arranged in the liquidbath to maintain the bath at a temperature which will melt the hydratesreceived therein, and the source also extending substantially throughthe length of the gas flow path to the outlet so as to prevent hydratesfrom forming an obstruction to the gas flow at the outlet comprising,

a direct source of heat operated at low pressure,

and a chamber of heat exchange liquid about the low pressure source 'ofheat and in heat exchange contact with the liquid bath and with the gasflowing to the outlet;

and a conduit connected to the chamber of heat exchange liquid at twopoints to provide a circuit for the heat exchange liquid to circulate asit is heated by the direct source of heat.

4. A low temperature separation system for high pressure hydrocarbonwell streams including;

a [high pressure] vessel receiving the well stream;

a choke through which the well stream is received into the [highpressure] vessel and reduced in pressure to condense the preponderantpart of the hydrocarbons and dehydrate the gaseous portion of the wellstream;

a liquid bath in the [high pressure] vessel arranged to receive hydratesdirectly therein as the hydrates are formed when the pressure of thewell stream is reduced;

an outlet for the dehydrated gas above the level of the liquid bath;

and a source of heat mounted in the vessel and arranged in the liquidbath to maintain the bath at a temperature which will melt the hydratesreceived therein, and the source also extending substantially throughthe length of the gas flow path to the outlet so as to prevent hydratesfrom forming an obstruction to the gas flow at the outlet comprising,

a direct source of heat operated at low pressure,

and a chamber of heat exchange liquid about the low pressure source ofheat and in heat exchange contact with the liquid bath and with the gasflowing to the outlet;

a conduit connected to the chamber of heat exchange liquid at two pointsto provide a circuit for the heat exchange liquid to circulate as it isheated by the source of heat;

and a jacket about the choke and communicating with the conduit to passthe heat exchange liquid externally about the choke and in heat exchangewith the choke.

[5. A low temperature separation system for high pressure hydrocarbonwell streams including,

a high pressure vessel which is generally elongated in the verticaldirection and receiving the well stream,

a choke through which the well stream is received into the high pressurevessel and reduced in pressure to condense the preponderant part of thehydrocarbons and dehydrate the gaseous portion of the Well stream,

a liquid bath in the lower portion of the high pressure vessel arrangedto receive hydrates directly therein as the hydrates are formed when thepressure of the well stream is reduced,

an outlet for the dehydrated gas above the level of the liquid bath,

and a source of heat which is generally elongated in the verticaldirection and mounted in the vessel so as to be partially emersed in theliquid bath, and the source also extending through a substantial length8 of the gas flow path to the outlet so as to prevent hydrates fromforming an obstruction to the gas fio at the outlet] 6. A lowtemperature separation system for high pressure hydrocarbon well streamsincluding;

a [high pressure] vessel which is generally elongated in the verticaldirection and receiving the well stream;

a choke through which the well stream is received into the [highpressure] vessel and reduced in pressure to condense the preponderantpart of the hydrocarbons and dehydrates the gaseous portion of the wellstream;

a liquid bath in the lower portion of the [high pressure] vesselarranged to receive hydrates directly therein as the hydrates are formedwhen the pressure of the well stream is reduced;

an outlet for the dehydrated gas above the level of the liquid bath;

and a source of heat which is generally elongated in the verticaldirection and mounted in the vessel so as to be partially emersed in theliquid bath, and the source also extending through a substantial lengthof the gas flow path to the outlet so as to prevent hydrates fromforming an obstruction to the gas flow at the outlet comprising,

a direct source of heat operated at low pressure and in elongated formalong the axis of the vessel;

and a chamber -of heat exchange liquid about the direct source of heatand between the direct source of heat and the liquid bath and betweenthe direct source of heat and [high pressure] gas space of the vessel.

7. A low temperature separation system for high pressure hydrocarbonWell streams including;

a [high pressure] vessel which is generally elongated in the verticaldirection and receiving the well stream;

a choke through which the well stream is received into the [highpressure] vessel and reduced in pressure to condense the preponderantpart of the hydrocarbons and dehydrate the gaseous portion of the wellstream;

a liquid bath in the lower portion of the [high pressure] vesselarranged to receive hydrates directly therein as the hydrates are formedwhen the pressure of the well stream is reduced;

an outlet for the dehydrated gas above the level of the liquid bath;

a source of heat which is generally elongated in the vertical directionand mounted in the vessel so as to be partially emersed in the liquidbath, and the source also extending through a substantial length of thegas fiow path to the outlet so as to prevent hydrates from forming anobstruction to the gas flow at the outlet comprising,

a direct source of heat operated at low prsesure and in elongated formalong the axis of the vessel,

and a chamber of heat exchange liquid about the direct source of heatand between the direct source of heat and the liquid bath and betweenthe direct source of heat and [high pressure] gas space of the vessel;

and a conduit connected to the chamber of heat exchange liquid at a highpoint and a low point and extending external of the vessel to provide acircuit for the heat exchange liquid to circulate as it is heated by thesource of heat.

8. A low temperature separation system for high pressure hydrocarbonwell streams including;

a [high pressure] vessel which is generally elongated in the verticaldirection and receiving the well stream;

a choke through which the well stream is received into the [highpressure] vessel and reduced in pressure to condense the p'reponderantpart of the hydrocarbons andv dehydrate the gaseous portion of the wellstream;

a liquid bath in the lower portion of the [high pressure] vesselarranged to receive hydrates directly therein as the hydrates are formedwhen the pressure of the well stream is reduced;

an outlet for the dehydrated gas above the level of the liquid bath;

a source of heat which is generally elongated in the vertical directionand mounted in the vessel so as to be partially emersed in the liquidbath, and the source also extending through a substantial length of thegas flow path to the outlet so as to prevent hydrates from forming anobstruction to the gas flow at the outlet comprising,

a direct source of heat operated at low pressure and in elongated formalong the axis of the vessel,

and a chamber 'of heat exchange liquid about the direct source of heatand between the direct source of heat and the liquid bath and betweenthe direct source of heat and [high pressure] gas space of the vessel;

a conduit connected to the chamber of heat exchange liquid at a highpoint and a low point and extending external of the vessel to'provide acircuit for the heat exchange liquid to circulate as it is heated by thesource of heat;

and a jacket about the choke and communicating with the conduit to passthe heat exchange liquid externally about the choke and in heat exchangewith the choke,

9. A low temperature separation system for high pressure hydrocarbonwell streams including;

a [high pressure] vessel which is generally elongated in the verticaldirection and receiving the well stream;

a choke through which the well stream is received into the [highpressure] vessel and reduced in pressure to condense the preponderantpart of the hydrocarbons and dehydrate the gaseous portion of the wellstream;

a liquid bath in the lower portion of the [high pressure] vesselarranged to receive hydrates directly therein as the hydrates are formedwhen the pressure of the well stream is reduced;

an outlet for the dehydrated gas the liquid bath;

a source of heat which is generally elongated in the vertical directionand mounted in the vessel so as to be partially emersed in the liquidbath, and the source also extending through a substantial length of thegas flow path to the outlet so as to prevent hydrates from forming anobstruction to the gas flow at the outlet comprising,

a direct source of heat operated at low pressure and in elongated formalong the axis of the vessel,

and a chamber of heat exchange about the direct source of heat andbetween the direct source of heat and the liquid bath and between thedirect source of heat and the [high pressure] gas space of the vessel;

and a plurality of fins extending from the chamber of heat exchangeliquid into the bath, whereby the heat from the source which passesthrough the heat exchange liquid is dissipated into the bath byconductionwith the fins at the plurality of contact points with thefins.

10. A low temperature separation system for high presabove the level ofsure hydrocarbon well streams including;

a [high pressure] vessel which is generally elongated in the verticaldirection and receiving the well stream, a choke through which the wellstream is received into the [high pressure] vessel and reduced inpressure to condense the preponderant part of the hydrocarbons anddehydrate the gaseous portion of the Well stream; a liquid bath in thelower portion of the [high pressure] vessel arranged to receive hydratesdirectly therein as the hydrates are formed when the pressure of thewell stream is reduced;

an outlet for the dehydrated gas above the level of the liquid bath;

a source of heat which is generally elongated in the vertical directionand mounted in the vessel so as to be partially emersed in the liquidbath, and the source also extending through a substantial length of thegas flow path to the outlet so as to prevent hydrates from forming anobstruction to the gas flow at the outlet comprising,

a direct source of heat operated at low pressure and in elongated formalong the axis of the vessel,

and a chamber of heat exchange liquid about the direct source of heatand between the direct source of.

heat and the liquid bath and between the direct source of heat and [highpressure] gas space of the vessel; and a vertical circular bafflemounted about the source of heat and at the level of the choke todeflect the well stream of reduced pressure downward toward the surfaceof the bath while insulating the cooled well stream from the heat of thechamber of heat exchange liquid and to then deflect the gaseous portionof the well stream upward toward the outlet for the stripped anddehydrated gas and into heat exchange with the chamber of heat exchangeliquid. 11. A low temperature separation system for high pressurehydrocarbon well streams including,

a [high pressure] vessel which is generally elongated in the verticaldirection and receiving the well stream,

a choke through which the well stream is received into the [highpressure] vessel and reduced in pressure to condense the preponderantpart of the hydrocarbons and dehydrate the gaseous portion of the wellstream,

a liquid bath in the lower portion of the [high pressure] vesselarranged to receive hydrates directly therein as the hydrates are formedwhen the pressure of the well stream is reduced,

an outlet for the dehydrated gas above the level of the liquid bath,

a source of heat which is generally elongated in the vertical directionand mounted in the vessel so as to be partially emersed in the liquidbath, and the source also extending through a substantial length of thegas flow path to the outlet so as to prevent hydrates from forming anobstruction to the gas flow at the outlet comprising,

a firetube heated with fluid fuel at substantially atmosphericconditions and extended axially through the vessel,

and a jacket about the firetube for heat exchange liquid between thefiretube and the liquid bath and between the firetube and [highpressure] gas space of the vessel.

12. A method of producing a predominantly gaseous hydrocarbon highpressure well stream to pipe line pressure including,

heating a reservoir of heat exchange liquid,

heat exchanging between the well stream and reservoir liquid indirectlyto elevate the well stream temperature the amount which will controlhydrate formution in the gaseous portion of the well stream when thepressure of the well stream is reduced to pipe line pressure,

reducing the high pressure of the well stream to pipe line pressure,

introducing the well stream at pipe line pressure into a separatorvessel having the capacity which will pro vide for separation of thestream into a: gaseous portion and a liquid portion,

removing the gaseous portion of the well stream from the separatorvessel to a pipe line,

passing heated liquid of the reservoir through a con- I 1 1 tinuousclosed circuit in indirect heat exchange with the separated liquidportion in the lower portion of the separator vessel with the force ofthermosiphonic circulation, sensing the temperature of the separatedliquid portion of the stream in the separator vessel,

7 and regulating the heating of the reservoir liquid with thetemperature of the heated liquid portion separated from the well stream.13. A system for producing a predominantly gaseous hydrocarbon highpressure well stream to pipe line pressure including,

a reservoir of heat exchange liquid,

a heater for the liquid of the reservoir,

an inlet conduit from the well for the well stream controlled inindirect heat exchange with the heat exchange liquid of the reservoir toelevate the well stream temperature the amount which will controlhydrate formation in the gaseous portion of the well stream when thepressure of the well stream is subsequently reduced to pipe linepressure,

a choke in the inlet conduit through which the high pressure of the wellstream is reduced to pipe line pressure,

a vessel connected to the inlet conduit downstream of the choke toreceive the well stream at pipe line pressure and provide the capacitywhich will separate the gaseous portion of the well stream from theliquid portion,

an outlet conduit from' the vessel through which the gaseous portion ofthe well stream is removed to a pipe line,

a continuous closed conduit connecting upper and lower portions of thereservoir and controlled in heat exchange relation with the lowerportion of the vessel to flow reservoir liquid with the force ofthermosip'honic circulation in indirect heat exchange with the separatedliquid portion,

whereby the temperature of the separated liquid portion is elevated highenough to prevent freezing the liquid portion while hydrate formation isbeing controlled in the gaseous portion by the heating of the inletconduit before the separated liquid portion is removed from the vesselto a pipe line,

and means sensing the temperature of the separated liquid portion of thewell stream and arranged to control the heating of the reservoir as thereservoir supplies heat to both the inlet conduit and the sepa-,

rated liquid.

References Cited by the Examiner The following references, cited by theExaminer, are of record in the patented file of this patent or theoriginal NORMAN YUDKOFF, Primary Examiner.

